The present invention is directed to a drive mechanism for rotating a satellite dish assembly through an arc of between 165.degree. and 180.degree.. Presently used drive assemblies are of the linear actuator type or the "horizon-to-horizon mount" type. The linear actuator type is either a manually operated screw jack or also may include a motor drive therefor. A common problem with this type of drive is that often the weight of the satellite dish or severe weather may damage the drive assembly. The linear actuator has a movable shaft which is pivotally connected at one end to the dish frame, and which must be protected from moisture and dust, as well as freezing temperatures. A small amount of wear or looseness at the pivots or in the drive screw causes extreme aiming problems, such that the dish assembly may no longer be directed skyward at the proper azimuth.
The horizon-to-horizon type of assembly employs heavy duty, close tolerance gearing directly mounted to the dish assembly, or alternatively uses sprockets and chains. These types of drives perform well, and are accurate in the long term, but are quite expensive. Precision gear boxes, isolated from ambient conditions, generally are free from dust and dirt problems. However, there are very expensive. Open drives are not isolated, and, therefore, suffer from damage due to ambient conditions. Thus, premature wear occurs. Further, there exists the same problem with all prior art types of assemblies, in that wear causes looseness, which magnifies slack, and thus compounds aiming problems.